In the ingredient descriptions: Good means that I like to see this in a product's list of ingredients. Okay means this product appears safe for a curly person like me to use. Caution means that this ingredient may not be good in some hair care products, or for some people. Avoid means this ingredient may hurt your hair. If you see this ingredient in a hair product, it's best to put it down and walk away.

Hydrolyzed Elastin(aka Elastin)Okay
Known for being a great moisturizing and conditioning ingredient. It’s a humectant, and it also has marketing appeal because it’s a natural ingredient. It help improves the feel of hair that’s been damaged. It’s known for improving the glossiness, body, and makes hair easier to comb. It may also reduce the irritation caused by other ingredients in the product.

Elastin is a protein that’s found in animal connective tissue that’s needed to be elastic. In order for it to work in hair, it has to be water-soluble. To make it water soluble, it’s broken down (hydrolyzed) by a mild base or heat. It’s available as a yellow or dark yellow, clear liquid or powder [Hunting (Conditioning) pages 236-237].
See also:ProteinElastinHydrolyzedSource(s): Hunting